Reaction-type steam turbine

ABSTRACT

Disclosed is a reaction-type steam turbine, including: a housing provided at a first side thereof with a steam inlet tube and at a second side thereof with a steam outlet tube, the housing having a space formed therein; and a turbine shaft provided to pass through the space of the housing, with a plurality of disk blades fitted over the turbine shaft, wherein a guide blade assembly is coupled to the turbine shaft at a position between a duct of the steam inlet tube and the disk blades, the guide blade assembly guiding steam introduced through the steam inlet tube into the space of the housing toward the disk blades.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a continuation of PCT/KR2016/005228, filed May 18, 2016, which claims priority to Korean Application No. 10-2015-0179105, filed Dec. 15, 2015, the entire teachings and disclosure of which are incorporated herein by reference thereto.

TECHNICAL FIELD

The present invention relates generally to a reaction-type steam turbine and, more particularly, to a reaction-type steam turbine capable of removing a vortex phenomenon in a housing, and maximizing energy output by reducing an initial load against a rotation of a turbine shaft.

BACKGROUND ART

As well known in the art, a reaction-type steam turbine is a machine suitable for medium and small capacity prime movers because it obtains rotational energy from reaction of steam energy being discharged, and has a simple structure and high thermal efficiency.

For example, Korean Patent Application Publication No. 10-2012-0047709 (published on May 14, 2012), Korean Patent Application Publication No. 10-2013-0042250 (published on Apr. 26, 2013), and Korean Patent No. 10-1229575 (registered on Jan. 29, 2013) all disclose examples of the reaction-type turbine.

FIG. 1 is a perspective view showing a part of a reaction-type steam turbine according to the related art, and FIG. 2 is a front cross-sectional view showing the reaction-type steam turbine.

As shown in FIGS. 1 and 2, the steam turbine includes a housing 10, a turbine shaft 20 rotatably supported by the housing 10 in the housing 10, and a plurality of disk blades 30 installed in the housing 10 and integrally rotating with the turbine shaft 20, the disk blades being arranged in parallel along the lengthwise direction of the turbine shaft 20.

Herein, the housing 10 is provided with a steam inlet tube 11 and a steam outlet tube 12, and steam introduced through the steam inlet tube 11 rotates the plurality of disk blades 30 while sequentially passing through the disk blades 30 to drive the turbine shaft 20, and then is discharged through the steam outlet 12.

Here, as shown in FIG. 2, each of the disk blades 30 is provided with a nozzle hole 31 and an inlet hole 32, such that when steam introduced into the inlet hole 32 is discharged to the nozzle hole 31, the disk blade 30 is rotated by reaction of the discharged steam.

Here, in accordance with this principle, the steam discharged from the nozzle hole 31 of each disk blade 30 enters the inlet hole 32 of the adjacent disk blade 30, thereby rotating the disk blade 30. Consequentially, all the disk blades 30 are rotated due to reaction of the steam, thereby rotating the turbine shaft 20 connected to the plurality of disk blades 30 to perform power generation.

On the other hand, the aforementioned conventional reaction-type steam turbine has the following problems.

The steam introduced through the steam inlet tube 11 is introduced into a turbine entrance 13 and then must be diverted toward the inlet hole 32 of the disk blade 30 (toward the right side in the drawing). However, the steam introduced through the steam inlet tube 11 may fail to be diverted to the disk blades 30 from the turbine entrance 13, and thus as shown in FIG. 3, a vortex phenomenon occurs due to steam that swirls in the turbine entrance 13.

Thus, since steam may fail to efficiently flow into the disk blades 30, it is difficult to maximize the rotational output of the turbine shaft 20.

Further, due to the vortex phenomenon, there is a problem that the friction loss is large.

BRIEF SUMMARY

Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide a reaction-type steam turbine, in which a guide blade assembly is installed on a turbine shaft at a position where a turbine entrance is provided such that steam introduced through the turbine entrance is automatically guided to disk blades, thereby removing a vortex phenomenon and maximizing the output of the turbine shaft.

In order to accomplish the above object, the present invention provides a reaction-type steam turbine, including: a housing provided at a first side thereof with a steam inlet tube and at a second side thereof with a steam outlet tube, the housing having a space formed therein; and a turbine shaft provided to pass through the space of the housing, with a plurality of disk blades fitted over the turbine shaft, wherein a guide blade assembly is coupled to the turbine shaft at a position between a duct of the steam inlet tube and the disk blades, the guide blade assembly guiding steam introduced through steam inlet tube into the space of the housing toward the disk blades.

The guide blade assembly may be provided with a plurality of drag blades radially arranged along a circumference of the turbine shaft, and facing the steam introduced through the steam inlet tube.

Each of the drag blades of the guide blade assembly may be formed such that an end of each drag blade is bent toward the steam inlet tube in a curved shape, such that a flow of the steam is guided to flow only toward the disk blades.

The space of the housing may include: a turbine entrance directly connected to the duct of the steam inlet; and turbine spaces provided at a side of the turbine entrance, and arranged such that the turbine shaft having the plurality of disk blades is placed perpendicular to the steam inlet tube, and the guide blade assembly is coupled to the turbine shaft at a position where the turbine entrance is provided.

The reaction-type steam turbine according to the present invention has the following effects.

First, since the guide blade assembly for guiding steam introduced through the steam inlet tube to the disk blades is provided at a position where the turbine entrance is provided in the housing, a vortex phenomenon is removed.

In other words, since the flowing direction of steam introduced into the turbine entrance from the steam inlet tube can be directly diverted to the disk blades by the guide blade assembly, the steam can be introduced into the disk blades without staying in the turbine entrance. Accordingly, a vortex phenomenon occurring due to a steam swirling can be removed.

Consequentially, it is possible to prevent friction loss caused by the vortex phenomenon, and thereby it is possible to realize improved energy efficiency and to maximize rotational output of the turbine shaft.

Second, since the turbine shaft can be rotated firstly by the rotation of the guide blade assembly prior to rotation of the disk blades by the steam inflow, it is possible to reduce the load required to initially start the turbine shaft.

In other words, since the turbine shaft can be rotated firstly by pressure applied to the guide blade assembly due to the pressure-feeding force of steam initially introduced straight from the steam inlet tube, it is possible to reduce the load required when the turbine shaft is secondarily and earnestly rotated by the rotation of the disk blades.

Third, as described above, since the rotational force of the turbine shaft is increased by using the pressure-feeding force of the steam that rotates the guide blade assembly, the rotational force of the turbine shaft can be doubled in comparison with the rotational force of the turbine shaft that is rotated only by the reaction force of the disk blades in the related art.

Consequentially, there is an effect that the output of the turbine can be maximized.

Fourth, since the guide blade assembly is provided with the drag blades that face the direction in which steam is introduced, it is possible to increase the rotational output of the turbine shaft.

In other words, since the guide blade assembly is structured to rotate through drag of the steam, the rotational output of the turbine shaft can be maximized.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing an inside of a reaction-type steam turbine according to the related art;

FIG. 2 is a partial cross-sectional view showing steam flow through disk blades of the reaction-type steam turbine according to the related art;

FIG. 3 is a schematic view showing a state in which a vortex phenomenon occurs in the reaction-type steam turbine according to the related art;

FIG. 4 is a view showing an inside of a reaction-type steam turbine according to a preferred embodiment of the present invention;

FIG. 5 is an enlarged perspective view showing guide blade assembly of the reaction-type steam turbine according to the preferred embodiment of the present invention; and

FIG. 6 is a schematic view showing a state in which steam is introduced into the reaction-type steam turbine according to the preferred embodiment of the present invention.

DETAILED DESCRIPTION

All terms or words used in the specification and claims have the same meaning as commonly understood by one of ordinary skill in the art to which inventive concepts belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, a reaction-type steam turbine according to a preferred embodiment of the present invention will be described with reference to FIGS. 4 to 6.

The reaction-type steam turbine has a technical feature wherein a turbine shaft is provided with a guide blade assembly whereby a direction of steam being introduced straight can be diverted to disk blades.

As shown in FIG. 4, the reaction-type steam turbine includes a housing 100, a turbine shaft 200, disk blades 300, and a guide blade assembly 400.

The housing 100 provides a space in which the disk blades 300 are rotated by a reaction force of steam, and is provided at a first side thereof with a steam inlet tube 110 and at a second side thereof with a steam outlet tube 120.

The steam inlet tube 110 forms a duct through which steam is introduced into the housing 100, and the steam outlet tube 120 forms a duct through which the steam introduced into the housing 100 is discharged from the disk blades 300.

The housing 100 is provided therein with a space 130 in which the turbine shaft 200 and the disk blades 300 are installed.

The space 130 includes a turbine entrance 131 and turbine spaces 132.

The turbine entrance 131 defines an entrance space through which steam introduced through the steam inlet tube 110 passes before it is transferred to the turbine spaces 132, thereby forming a space directly connected to the duct of the steam inlet tube 110 in a straight line.

Herein, the turbine spaces 132 provide spaces in which the disk blades 300 are installed and the disk blades 300 are rotated, and are provided at a side of the turbine entrance 131.

As shown in FIG. 4, the side of the turbine entrance 131 refers to a side perpendicular to the duct of the steam inlet tube 110.

In addition, the turbine spaces 132 are structured to be connected to the duct of the steam outlet tube 120.

Next, the turbine shaft 200 is rotated by the rotational force of both the disk blades 300 and the guide blade assembly 400 to provide a power output, and is installed inside the housing 100.

Herein, as shown in FIG. 4, the turbine shaft 200 is installed to pass through the turbine entrance 131 and the turbine spaces 132 of the housing 100.

Next, the disk blades 300 serve to provide power for rotating the turbine shaft 200. The disk blades are rotated by the reaction force generated when steam introduced through the steam inlet tube 110 flows in and out of the disk blades 300, thereby generating power for rotating the turbine shaft 200.

A plurality of disk blades 300 are fitted over the turbine shaft 200 along the axis of the shaft, and the disk blades are placed in the respective turbine spaces 132 of the housing 100.

Herein, the disk blades 300 are formed in a circular shape, and each of the disk blades is provided with an inlet hole through which steam is introduced and a nozzle hole through which steam is discharged. This structure of the disk blades 300 remains the same as that of the related art described above.

Next, the guide blade assembly 400 serve to divert a flowing direction of steam introduced through the steam inlet tube 110 to the turbine spaces 132, and is placed in the turbine entrance 131.

In other words, the guide blade assembly 400 serves to interfere with steam introduced straight to the turbine entrance 131 through the steam inlet tube 110 and to transfer the steam to the turbine spaces 132 placed at the side of the turbine entrance 131.

As shown in FIG. 4, the guide blade assembly 400 is coupled to the turbine shaft 200 at a position where the turbine entrance 131 is provided.

The configuration of the guide blade assembly 400 will be described in detail with reference to FIG. 5.

The guide blade assembly 400 includes a blade hub 410 that is coupled to the turbine shaft 200 and a plurality of drag blades 420 that are radially arranged along the circumference of the blade hub 410.

The blade hub 410 is structured to be coupled to the turbine shaft 200, and has a cylindrical shape having an inner diameter corresponding to a diameter of the turbine shaft 200.

Further, the drag blades 420 are configured to face steam introduced into the turbine entrance 131 through the steam inlet tube 110, and serve to guide the steam to the turbine spaces 132.

In other words, the guide blade assembly 400 is structured such that the drag blades 420 face the flowing direction of steam, thereby maximizing the effect of rotating the turbine shaft 200 due to the pressure of steam, and also serves to divert the flowing direction of steam to the turbine spaces 132 where the disk blades 300 are placed.

Herein, a rotation of the guide blade assembly 400 is generated by drag of steam, so that a rotational output of the turbine shaft 200 can be maximized.

Here, the plurality of drag blades 420 is radially arranged along the circumference of the blade hub 410.

Here, as shown in FIG. 5, each of the drag blades 420 includes a bent portion 421 and a straight portion 422.

The bent portion 421 serves to divert steam introduced into the turbine entrance 131 to the straight portion 422, and constitutes a first side of the drag blades 420.

Here, the first side of the drag blades 420 refers to a side opposite to the turbine spaces 132 where the disk blades 300 are placed, and the bent portion 421 is bent in a direction in which steam is introduced.

As such, since the first side of the drag blades 420 is bent in the direction in which steam is introduced, steam introduced into the turbine entrance 131 is guided by the bent portion 421, so that the steam can be always directed to the turbine spaces 132.

Here, the bent portion 421 of the drag blades 420 may be formed in a curved shape.

This is to flexibly divert the direction of steam introduced straight into the turbine entrance 131.

The straight portion 422 serves to guide steam guided by the bent portion 421 directly to the turbine spaces 132, and constitutes a second side of the drag blades 420.

Hereinafter, the operation of the reaction-type steam turbine having the above configuration will be described.

Steam is supplied through the steam inlet tube 110, and then the steam is pressure-fed to the turbine entrance 131 through the duct of the steam inlet tube 110.

Here, the steam hits the drag blades 420 of the guide blade assembly 400, and is then guided along both the bent portion 421 and the straight portion 422 to the right side (turbine spaces side) in the drawing (FIG. 4).

Here, the drag blades 420 of the guide blade assembly 400 guide the steam to the turbine spaces 132 to divert the direction of the steam, and simultaneously rotate by receiving pressure of the steam.

In other words, the steam introduced through the steam inlet tube 110 also serves to firstly rotate the turbine shaft 200 by applying pressure to the guide blade assembly 400.

As such, by firstly rotating the turbine shaft 200 by using the steam pressure, the load required to initially rotate the turbine shaft 200 can be reduced, thereby realizing improved energy efficiency when rotating the turbine shaft 200.

Then, the steam introduced through the steam inlet tube 110 continuously pressurizes the drag blades 420 of the guide blade assembly 400 to rotate the turbine shaft 200, and is simultaneously introduced into the inlet holes of the disk blades 300 provided at the turbine spaces 132.

Thereafter, the steam rotates the disk blades 300 while flowing in and out of the plurality of disk blades 300, thereby secondarily rotating the turbine shaft 200.

Through this series of processes, the output of the turbine shaft is achieved.

As described above, the reaction-type steam turbine according to the present invention has a technical feature wherein the guide blade assembly 400 is coupled to the turbine shaft 200 at a position where the turbine entrance 131 is provided.

Accordingly, the steam introduced straight into the housing can be naturally guided toward the disk blades 300 after hitting the guide blade assembly 400, so that it is possible to remove a vortex phenomenon occurring due to steam that swirls in the turbine entrance 131 and thereby reduce the energy loss.

Also, due to the pressure of steam initially introduced into the housing, the turbine shaft can be firstly rotated by the rotation of the guide blade assembly. Thus, it is possible to reduce the load required when the turbine shaft is secondarily and earnestly rotated by the rotation of the disk blades, thereby realizing improved energy efficiency when rotating the turbine shaft.

Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. 

1. A reaction-type steam turbine, comprising: a housing provided at a first side thereof with a steam inlet tube and at a second side thereof with a steam outlet tube, the housing having a space formed therein; and a turbine shaft provided to pass through the space of the housing, with a plurality of disk blades fitted over the turbine shaft, wherein a guide blade assembly is coupled to the turbine shaft at a position between a duct of the steam inlet tube and the disk blades, the guide blade assembly guiding steam introduced through the steam inlet tube into the space of the housing toward the disk blades.
 2. The reaction-type steam turbine of claim 1, wherein the guide blade assembly is provided with a plurality of drag blades radially arranged along a circumference of the turbine shaft, and facing the steam introduced through the steam inlet tube.
 3. The reaction-type steam turbine of claim 2, wherein each of the drag blades of the guide blade assembly is formed such that an end of each drag blade is bent toward the steam inlet tube in a curved shape, such that the steam is guided to flow only toward the disk blades.
 4. The reaction-type steam turbine of claim 1, wherein the space of the housing includes: a turbine entrance directly connected to the duct of the steam inlet; and turbine spaces defined at a side of the turbine entrance, with the disk blades installed in the respective turbine spaces, the turbine spaces being arranged such that the turbine shaft having the plurality of disk blades is placed perpendicular to the steam inlet tube, and the guide blade assembly is coupled to the turbine shaft at a position where the turbine entrance is provided.
 5. The reaction-type steam turbine of claim 2, wherein the space of the housing includes: a turbine entrance directly connected to the duct of the steam inlet; and turbine spaces defined at a side of the turbine entrance, with the disk blades installed in the respective turbine spaces, the turbine spaces being arranged such that the turbine shaft having the plurality of disk blades is placed perpendicular to the steam inlet tube, and the guide blade assembly is coupled to the turbine shaft at a position where the turbine entrance is provided.
 6. The reaction-type steam turbine of claim 3, wherein the space of the housing includes: a turbine entrance directly connected to the duct of the steam inlet; and turbine spaces defined at a side of the turbine entrance, with the disk blades installed in the respective turbine spaces, the turbine spaces being arranged such that the turbine shaft having the plurality of disk blades is placed perpendicular to the steam inlet tube, and the guide blade assembly is coupled to the turbine shaft at a position where the turbine entrance is provided. 